Portable chargers vs on-board chargers

[user 29]

I’m running the typical 12V + 24V set up.
I’m debating whether to pick up another portable charger for a total of 3 OR should I just bite the bullet and set-up an on-board system?
Safety is Priority 1. Convenience is secondary. Is there plug it in and forget it option? What are ballpark $$$?
Thanks!

 

[MrGiggles]

Onboard is the way to go as far as I'm concerned. Just plug it in when you get home and unplug when it's done.

Plus it is hard to find a portable charger/maintainer that will put out the amps that some of the bigger onboard units can. The faster those batteries get recharged, the better. I like 5 amps minimum, 10 is better.

 

[CRS]

I was told yesterday by a Minn Kota tech that when charging batteries they should be disconnected from all electronics including motors. The reason being said he was that the charge voltage is higher than the operating voltage and that higher voltage makes it's way to the circuit boards. This I was told could damage or destroy the circuitry. I have never had this problem that I know of for sure. I did need to replace a board on a Minn Kota when it fried unexpectedly. Not wanting to risk my new electronics I will be installing the necessary switches. Just thought I would pass this along to everyone.

 

[LDUBS]

I was told yesterday by a Minn Kota tech that when charging batteries they should be disconnected from all electronics including motors. The reason being said he was that the charge voltage is higher than the operating voltage and that higher voltage makes it's way to the circuit boards. This I was told could damage or destroy the circuitry. I have never had this problem that I know of for sure. I did need to replace a board on a Minn Kota when it fried unexpectedly. Not wanting to risk my new electronics I will be installing the necessary switches. Just thought I would pass this along to everyone.

YIKES! fortunately I unplug my TM when not in use. But what about starter batteries? Lacking a master switch, it would be a PITA to isolate that battery.

 

[FuzzyGrub]

I know that MG has had the same warning on their trolling motors, so I've always unplugged. FF is always turned off, but mine can handle over-voltage. My son's new boat has a 90/65 Yamaha with much more electroncs than any of my other outboards, so I contacted them to make sure there was no issue. They indicated it has over voltage protection, and no need for a disconnect switch.

I've used Guest chargers for years, but wth the new boat trying out NOCO chargers. Very happy so far. I have a 10A X 2 on trolling motor batteries and a 5A on the starter battery, given it has an alternator and stays charged during our river runs.

For me, with multiple batteries, it is too much of a hassle moving a portable one around, and like to get them recharged as soon as I'm home. I sometimes cover the boat right away, which can make it a pain to get a portable off or switch to another battery.

 

[JNG]

I was told yesterday by a Minn Kota tech that when charging batteries they should be disconnected from all electronics including motors. The reason being said he was that the charge voltage is higher than the operating voltage and that higher voltage makes it's way to the circuit boards. This I was told could damage or destroy the circuitry. I have never had this problem that I know of for sure. I did need to replace a board on a Minn Kota when it fried unexpectedly. Not wanting to risk my new electronics I will be installing the necessary switches. Just thought I would pass this along to everyone.

This is correct. Both MK and MG say to disconnect electronics from the battery/batteries and this includes trolling motors!

I use a Century K3152-1 portable charger and have gotten excellent service from it.

 

[JNG]

Onboard is the way to go as far as I'm concerned. Just plug it in when you get home and unplug when it's done.

Plus it is hard to find a portable charger/maintainer that will put out the amps that some of the bigger onboard units can. The faster those batteries get recharged, the better. I like 5 amps minimum, 10 is better.

The Century K3152-1 puts out a full 10 amps when that option is selected.

 

[C&K]

The trolling motor on our boat is wired in direct to the batteries (no plug), but we have a 90A DC breaker for it under the hatch on the forward deck to turn it off. The starting battery under the stern hatch has a big disconnect switch built right into the battery box. That battery powers the electronics, lights, radios, bilge pumps, livewell and aerator pumps. I would not be comfortable without a disconnect switch on that battery. What if the starter relay on your outboard sticks, or one of the tilt/trim relays welds the contacts and sticks? We've had it happen before. Without that main disconnect, you could have a major melt-down on the water because some of the big circuits like you outboard starter motor are not fused.

We do have a 30A circuit with a switch on the panel that connects the trolling motor batteries to the starting battery in the event the starting battery would get too low to start the engine.

We live right on the lake so we don't load the boat up every day. It normally goes into the boat lift when we're docked. For charging when docked I turn off the main disconnect on the starting battery and throw the switch that connects all three together in 12V parallel. The shore charger is built into the boat lift and has a 15 ft cord that plugs into what most people would use as a trolling motor plug up in the bow. Then crank up the boat lift. The trolling motor is 24V but there's an isolator in that battery compartment under the bow hatch that connects them to the starting battery, and allows charging them, as two 12V's. Our shore charger is a Schumacher 30A.

It's illegal in most jurisdictions to run a 120V cord to a docked boat without all the proper grounding, galvanic isolators and USCG approved bulkhead connectors. DC connection can be made ship-to-shore with no restrictions as long as you don't use open alligator clips and the circuit is protected with the right size fuse for the size of wire.